In Australia, monitoring Helicoverpa species for resistance to the Cry2Ab toxin in second generation Bacillus thuringiensis (Bt) cotton has precisely fulfilled its intended function: to warn of increases in resistance frequencies that may lead to field failures of the technology. Prior to the widespread adoption of two‐gene Bt cotton, the frequency of Cry2Ab resistance alleles was at least 0.001 in H. armigera and H. punctigera. In the 5 years hence, there has been a significant and apparently exponential increase in the frequency of alleles conferring Cry2Ab resistance in field populations of H. punctigera. Herein we review the history of deploying and managing resistance to Bt cotton in Australia, outline the characteristics of the isolated resistance that likely impact on resistance evolution, and use a simple model to predict likely imminent resistance frequencies. We then discuss potential strategies to mitigate further increases in resistance frequencies, until the release of a third generation product. These include mandating larger structured refuges, applying insecticide to crops late in the season, and restricting the area of Bollgard II® cotton. The area planted to Bt‐crops is anticipated to continue to rise worldwide; therefore the strategies being considered in Australia are likely to relate to other situations.
Adaptive management of pest resistance by Helicoverpa species (Noctuidae) in Australia to the Cry2Ab Bt toxin in Bollgard II® cotton
S. Downes,R. Mahon,L. Rossiter,G. Kauter,Tracey Leven,G. Fitt,G. Baker
Published 2010 in Evolutionary Applications
ABSTRACT
PUBLICATION RECORD
- Publication year
2010
- Venue
Evolutionary Applications
- Publication date
2010-07-19
- Fields of study
Agricultural and Food Sciences, Medicine, Biology, Environmental Science
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
CITATION MAP
EXTRACTION MAP
CLAIMS
CONCEPTS
- bollgard ii cotton
Second-generation Bt cotton that expresses two Bt toxins, including Cry2Ab.
Aliases: two-gene Bt cotton, Bollgard II® cotton
- bollgard ii cotton area restriction
Limiting the planted area of Bollgard II cotton as a resistance-management tactic.
Aliases: restricting the area of Bollgard II cotton
- cry2ab bt toxin
A Bacillus thuringiensis toxin expressed in Bollgard II cotton that targets Helicoverpa larvae.
Aliases: Cry2Ab
- cry2ab resistance alleles
Alleles in Helicoverpa populations that reduce susceptibility to Cry2Ab.
Aliases: resistance alleles conferring Cry2Ab resistance
- helicoverpa armigera
A Helicoverpa moth species discussed as a cotton pest in Australia.
Aliases: H. armigera
- helicoverpa punctigera
A Helicoverpa moth species discussed as a cotton pest in Australia.
Aliases: H. punctigera
- helicoverpa species
The Helicoverpa pest group monitored in Australian cotton systems.
- late-season insecticide application
Insecticide use applied late in the season as a resistance-management tactic.
Aliases: applying insecticide to crops late in the season
- simple model
A simplified predictive model used to project future resistance allele frequencies.
- structured refuges
Designated non-Bt planting areas maintained alongside Bt cotton to slow resistance evolution.
Aliases: larger structured refuges, refuges
- third-generation product
A future next-generation Bt cotton product referenced as the point until which current mitigation is intended to last.
Aliases: third generation product
REFERENCES
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